1. Department of Respiratory Medicine, Hitachi General Hospital, Hitachi Ltd., Hitachi, Ibaraki, Japan
2. Research & Development Center, Osaka Medical College,Takatsuki, Osaka, Japan
3. Center for Public Health Sciences, National Cancer Center Japan, Chuo-ku, Tokyo, Japan
4. Department of Endoscopy, Tohoku Medical and Pharmaceutical University, Miyagino-ku, Sendai, Miyagi, Japan
5. Hitachi Health Care Center, Hitachi Ltd., Hitachi, Ibaraki, Japan
6. Hitachi Medical Education and Research Center, Thoracic Surgery, University of Tsukuba, Hitachi, Ibaraki, Japan
7. Epidemiology and Prevention, Center for Clinical Sciences, National Center for Global Health and Medicine, Shinjuku-ku, Tokyo, Japan